Lebanon's Iran-backed Hezbollah movement Tuesday called for a "day of rage" to condemn a strike on a Gaza Strip hospital as hundreds of demonstrators gathered at the French and US embassies in protest.

Hezbollah, an ally of Palestinian Islamist group Hamas, blamed the hospital attack on Israel, calling it a "massacre" and a "brutal crime", while Israel's army blamed a rocket misfired by Islamic Jihad, another Gaza-based militant group.

The health ministry in Gaza, ruled by Hamas militants at war with Israel, said at least 200 people were killed in an Israeli strike on the hospital where displaced people had sheltered in the coastal enclave.

"Let tomorrow, Wednesday, be a day of rage against the enemy," Hezbollah said in a statement, calling on fellow Muslims and Arabs to "move immediately to streets and squares to express intense anger".

The call came as hundreds of demonstrators gathered at the embassy of the United States in the suburb of Awkar, north of the capital, where they chanted "death to America" and "death to Israel", according to AFP correspondents.

Lebanese security forces fired tear gas to disperse protesters who hurled stones towards the embassy, many of them covering their faces with Palestinian keffiyeh scarves, the correspondents said.

Hundreds also gathered at the French embassy in Beirut, raising Palestinian flags and also hurling stones which piled up at the embassy's main entrance. 

Palestinian refugee camps in the southern cities of Sidon and Tyre also erupted in anger as Palestinian factions in Lebanon called for mass rallies on Wednesday to condemn the hospital strike.

Caretaker Prime Minister Najib Mikati declared Wednesday a national day of mourning.

lar/ho/giv